━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
【JWF News Vol.145】 Three typhoons in a row hit Hokkaido for the first time in recorded history
October 19, 2016
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
◇Contents◇
・Foreword In August 2016, Hokkaido was ravaged by torrential rains caused by three consecutive typhoons and a stationary extratropical cyclone
・Announcement from the Japan Water Forum
-Projects of JWF Fund 2016 Decided!
・Report from the Japan Water Forum
-JWF Fund a year-after follow-up
-The 10th edition of the Darvish Yu Water Fund Project has been completed!
-JWF Communication Lounge 2016
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
・Foreword In August 2016, Hokkaido was ravaged by torrential rains caused by three consecutive typhoons and a stationary extratropical cyclone
By Dr. Norihito Tambo, Vice President of the Japan Water Forum
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
As Hokkaido is located in the northernmost part of the Japanese archipelago, warm, humid air masses from the south rarely reach the island. Therefore, there is no rainy season there. On the western side (the Sea of Japan side) of the Hidaka Mountains, half of the precipitation consists of winter snow in. In contrast, on the plains lying east of the mountains, there is little snow and most of the spring runoff comes from melting snow on the mountainous backbone, the Daisetsu and the Hidaka Mountains. Therefore, we sometimes experience high water in the rivers during the snowmelt season. In the past, this was a disaster for residents living on the wetlands along the meandering primeval rivers: the Ishikari-gawa and the Teshio-gawa.
The annual mean precipitation in the main cities of Hokkaido is about 1,100mm. Compared with those of Tokyo (1,500mm) and Okinawa (2,000mm), this amount is very small. These cities have rarely experienced typhoon damage. The residents of Hokkaido, including me, feel threatened when there is a storm yielding more than 200mm of rain. This summer, three typhoons with precipitation of over 200mm hit Hokkaido one after another. In addition, two more typhoons swept across the neighboring region. In total, five typhoons plus an extratropical cyclone, which is a kind of cast-off shell from a typhoon, hit the area.
Looking back on history, a typhoon ravaged Hokkaido and brought heavy rain to the Ishikari-gawa River basin in September 1898. This record rainfall caused serious flooding in the region. It caused catastrophic damage to the development of Hokkaido. All areas along the main stream of the Ishikari-gawa River flowing from Kamikawa, its tributary Sorachi-gawa River and the Yubari-gawa River in addition to the flat land on both sides of the Horonui-gawa River, including Horomui Moor, were inundated. A huge lake appeared in the Ishikari-gawa River basin with a width of 40km, a length of 100km, and an area of 56,000 hectares. There was a heavy toll of 300 lives and 3,500 houses. Bridges and railways were swept away, one fifth of the area’s arable land was lost, and more than 10 thousand residents left Hokkaido. The route of the typhoon was almost the same as that of this year’s three typhoons. The development project for the area had failed.
However, as early as September of that same year, the president of the Hokkaido Association presented a petition to the Minister of Home Affairs entitled Flood Control for the Development of Hokkaido. In October, the Investigation Committee on Flood Control in Hokkaido was convened. Dr. Bunkichi Okazaki, who led the investigation and later became head of the office for flood control, had his own ideas about flood control in primeval rivers and responses to frozen rivers. The initial Ishikari River Flood Control Program was developed with his ideas about natural rivers in mind.
In August 1981, a typhoon submerged a paddy field zone in the Ishikari River basin. It was the most severe typhoon in 83 years. Following this, in preparation for future typhoons, the Ishikari River Basic Program was developed, in which the amount of precipitation and flooding water during typhoons was used as a standard in developing flood control programs. The construction of dam reservoirs, enhancement of levees, and excavation of river channels were implemented. In addition, water gates, pumping stations and retarding ponds were built in order to prevent internal flooding.
However, in August of this year, three typhoons, Chanthu, Nangka, and Mindulle, hit Hokkaido one after another, the first such occurrence in recorded history. They came straight towards the south end of the Hidaka Mountains from the Pacific Ocean, through the Tokachi Plain to the Sea of Okhotsk. The total amount of rainfall reached 500mm. Each typhoon was so large that its radius covered an area half as large as Hokkaido. Just after that, Typhoon Lionrock, straying off the Ogasawara islands, hit the coast of the Tohoku District. The typhoon disintegrated into an extratropical cyclone and stayed near the Oshima Peninsula for three days, dumping a great deal of rain, more than 500mm in total.
At the beginning of September, the only place that escaped typhoon damage was the city of Sapporo and its surrounding area. Though we had avoided a devastating breaking of levees along the main stream like the damage caused by the massive flooding of 1981, we can’t really claim to have dealt effectively with this series of typhoons.
I hope we will be able to gain a full understanding of the mechanism that is creating these new types of typhoons from the perspectives of historical climatology and hydrology.
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
・Announcement from the Japan Water Forum
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Projects of JWF Fund 2016 Decided!
Japan Water Forum (JWF) Fund managed through fees from corporate and individual members and donations is the initiative that supports grass-roots organizations to address water-related issues in developing countries. Since its establishment in 2005, 150 projects have been carried out so far.
In the JWF fund of this year, we have received 560 applications from 45 countries.
As the result of selection, we have decided to provide funds for 6 projects from 5 countries.
▼Please visit the following website for details▼
https://www.waterforum.jp/en/2016/1003/?p=2603
(Reported by Sae Ishihara, Manager)
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
・Report from the Japan Water Forum
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
JWF Fund a year-after follow-up
Through the JWF Fund, we put a priority on reacting to the issues and needs in the field efficiently and effectively.
To grasp the changes of the issues and needs after the completion of the projects, we have carried out follow-up observations of the projects in 2014, in which we expect to collect the information on effects and impacts of the projects.
In the first year of the follow-up observations, two organizations have willingly accepted our request and provided information of the current situation of the project implemented village.
You can find detail of the follow-up observation in our webpage.
▼Please visit the following website for details▼
https://www.waterforum.jp/en/2016/1006/?p=3727
(Reported by Sae Ishihara, Manager)
—————————————————————————————————
The 10th edition of the Darvish Yu Water Fund Project has been completed!
As the 10th project, we have carried out the activities for vulnerability reduction of desert communities in India through providing safe and sustainable sources of drinking water.
We would like to express gratitude towards Mr. Darvish and the donors to the Darvish Yu Water Fund for their kind understanding and support.
You can find detail of the project in our webpage.
▼Please visit the following website for details▼
https://www.waterforum.jp/en/2016/1019/?p=2759
(Reported by Sae Ishihara, Manager)
—————————————————————————————————
JWF Communication Lounge 2016
On September 26th JWF Communication Lounge 2016 was held in the meeting room of the JWF offices. Its purpose was to explore the possibilities of Japan’s support for the solution of water problems in Southeast Asia, as well as to share knowledge and experiences.
This time, we welcomed Professor Zulkifli Yusop from the University of Technology of Malaysia. We discussed the possibility of cooperation between Malaysia and Japan.
▼Please visit the following website for details▼
https://www.waterforum.jp/en/2016/1019/?p=3126
(Reported by Kei Sato, Manager)
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
▼JWF News Achives▼
https://www.waterforum.jp/en/news_en/newsletter_en
If you wish to post information on our bulletin board, or should you prefer not to receive further JWF News, please contact us. You can also get in touch regarding changes of address, or any other comments or requests.
■━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━■
JWF News Vol.145 October 19, 2016
Japan Water Forum
6th fl., 5-4 Nihonbashi-Hakozaki-cho, Chuo-ku, Tokyo, 103-0015
TEL: 03-5645-8040 FAX: 03-5645-8041
E-mail: news[at]waterforum.jp URL: https://www.waterforum.jp/en/
※Please change [at] to @
■━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━■
